Fire and burglar alarm



Jan. 20, 1953 H. c. SORENSEN FIRE AND BURGLAR ALARM Filed July 17, 1950Fig.

Harold 62 Sorensen IN VEN TOR.

Patented Jan. 20, 1953 UNITED STATES PTENT OFFICE FIRE AND BURGLAR ALARMHarold C. Sorensen, Manitowoc, Wis. Application July 17, 1950, SerialNo.174,215

3 Claims- This invention, comprises novel and useful improvements inalarms, and more, particularly. per-v tains to a combination fire andburglar alarm.

Various important objects of this invention are to provide a combinationfire and burglar alarm which is of compact and simple construction;which has an efficacious appearance; and in which the hammer brake armwill be released either in response to a predetermined high temperature,or in response to the passage of an intruder through a predeterminedarea.

An important feature of this invention resides in the provision of agong, a spring biased hammer for said gong, and a hammer brake arm whichis yieldingly biased out of its braking posiv tion, together with afusible member for retaining the arm in such braking position.

Yet another feature of this invention resides in the provision of analarm, in, accordance with the foregoing features, in which the fusiblemem-, her is releasably retained in a position to hold the brake arm inits braking position, together with a means for removing the fusiblemember, in response to a predetermined tension applied to a cord that isattached to the fusible member.

These, together with various ancillary objects and features of theinvention are attained by this device, a preferred embodiment of whichhas been illustrated by way of example only in the accompanyingdrawings, wherein:

Figure 1 is a front elevational view of the combination alarm;

Figure 2 is a rear elevational view of the alarm, with the back removedtherefrom to show the details of construction;

Figure 3 is a transverse sectional view of the alarm, takensubstantially on the plane 3--3 of Figure 2;

Figure 4 is a horizontal sectional view of the alarm, takensubstantially on the plane 4- of Figure 2;

Figure 5 is a fragmentary top plan view of the hammer brake arm shown inhammer arm releasing position; and,

Figure 6 is an enlarged fragmentary side elevational view of a portionof Figure 3 showing the manner in which a cord is attached to thefusible member.

Reference is now made more specifically to the accompanying drawingswherein like numer- P als designate like parts throughout the variousviews, and in which the combined fire and burglar alarm is designatedgenerally by the numeral [0.

The combination alarm I0 includes a spring actuated mechanism [2 whichconsists of fore ward and-rear mounting plates I4 and [-6 respectively,and between. which plates is rotatably j-ournaled an escapement wheelIS. The escapement wheel 18 is actuated by a main spring 28 through theintermediary of a gear train 22, which may be of any known construction,it merely being necessary to operatively connect the main spring 20 tothe escapement wheel I8.

A hell or gong 24 is mounted upon the front plate M, as by the U-shapedbracket 26 which is terminally attached to the front plate, and which isattached intermediate its ends to the bell 24 as by a rivet or bolt 28.A pallet 30 is pivotally mounted between the front and rear mountingplates is and [6, for movement about an axis parallel to .the axis ofrotation of the escapement wheel It, the pallet 30 operatively engagingthe escapement. wheel so that upon rotation of the latter the hammer arm32 which is attached to the pallet will be oscillated, the hammer head34 engaging the bell 24, thereby providing an acoustical alarm.

In order to restrict actuation ofthe hammer arm 32, there is provided abrake arm 36 which has one end 38 thereof secured to the front plate 14,as by fasteners 40. A locking finger 42 is attached to the arm 35, andextends transversely thereof, which finger is adapted to move in thepath of travel of the hammer arm 32, when the latter is beingreciprocated by the escapement wheel I8, so as to restrict movementthereof. It is intended that the brake arm 36 be resilient, and that itnormally urge the finger 42 out of the path of movement of the hammerarm 32. A transversely extending arm 44 is attached to the other end ofthe brake arm 36, which arm extends through a slot 45 in the rear wall48 of the alarm casing, and which has a transversely extending fingerportion 50 which is adapted to retain a fusible plug 52 such as wax orthe like, between the finger portion 50 and the rear wall 48 of thecasing. It is intended that the fusible block 52 be of such dimensionsthat when it is inserted between the rear wall 48 and the finger portion50, that the locking finger 42 will be disposed in the path of travel ofthe hammer arm 32. It will thus be apparent that the brake arm 36yield-ingly biases the fusible block 52 and retains the latter inposition between the finger and the rear wall.

It is intended that a cord such as 54 may be attached to the block 52,as by insertion through a bore 66 therein, whereby the fire alarm mayalso serve as a burglar alarm, the cord 54 being disposed across thepassageway or doorway, through which an intruder or burglar wouldprobably pass. Obviously, when tension is applied to the cord 54, thefusible block 52 will be removed from its braking position, whereby thebrake arm 36 will urge the locking finger 42 out of its hammer armengaging position. The bell 24, and the alarm mechanism I2 may be housedin a suitable casing which includes an apertured front wall 58 having aforaminous screen 60 secured thereto, as by the annular collar 62 whichis secured to the front wall by fasteners 64. Rearwardly extending sidewalls 66 are secured to the front wall 58, and are provided withreinforcing ribs 68, in the comers thereof, which ribs may be providedwith internally threaded bores to receive the fastening screws by meansof which the rear wall 48 is secured to the side walls 66 of the casing.From the foregoing, it is felt that the operation and construction ofthe device may be readily understood, and further discussion istherefore believed to be unnecessary. However, numerous modificationswill readily occur to those skilled in the art after a consideration ofthe foregoing specification and accompanying drawings, it is notintended to limit the invention to that shown and described, but allsuitable modifications may be resorted to falling within the scope ofthe appended claims.

Having described the invention, what is claimed as new is:

1. An alarm comprising a base, a spring actuated escapement wheelmounted on said base, a pallet engaging said wheel, a hammer operativelyconnected to said pallet for oscillatory movement in response torotation of said wheel, a bell disposed in the path of movement of saidhammer, a resilient arm having one end thereof fixedly attached to saidbase, a pin projecting laterally of said arm adjacent the free endthereof, said arm being movable in a plane transverse the plane ofmovement of said hammer and yieldingly urging said pin out of engagementwith said hammer, and means including a fusible body opposing movementof said arm and retaining said pin in engagement with said hammer.

2. An alarm comprising a base, a spring actuated escapement wheelmounted on said base, a pallet engaging said wheel, a hammer operativelyconnected to said pallet for oscillatory movement in response torotation of said wheel, a bell disposed in the path of movement of saidhammer, a resilient arm having one end thereof fixedly attached to saidbase, a pin projecting laterally of said arm adjacent the free endthereof, said arm being movable in a plane transverse the plane ofmovement of said hammer and yieldingly urging said pin out of engagementwith said hammer, and means including a fusible body opposing movementof said arm and retaining said pin in engagement with said hammer, saidbase including a wall disposed parallel to the plane of movement of saidhammer, a relatively transverse end portion on the free end of said armand disposed in the plane of movement thereof, said end portion slidablyextending through said wall, a relatively transverse finger on the endof said end portion remote from said arm, and a fusible body disposedbetween said finger and said wall.

3. An alarm comprising a base, a spring actuated escapement wheelmounted on said base, a pallet engaging said wheel, a hammer operativelyconnected to said pallet for oscillatory movement in response torotation of said wheel, a bell disposed in the path of movement of saidhammer, a resilient arm having one end thereof fixedly attached to saidbase, a pin projecting laterally of said arm adjacent the free endthereof, said arm being movable in a plane transverse the plane ofmovement of said hammer and yieldingly urging said pin out of engagementwith said hammer, and means including a fusible body opposing movementof said arm and retaining said pin in engagement with said hammer, saidbase including a wall disposed parallel to the plane of movement of saidhammer, a relatively transverse end portion on the free end of said armand disposed in the plane of movement thereof, said end portion slidablyextending through said wall, a relatively transverse finger on the endof said end portion remote from said arm, and a fusible body disposedbetween said finger and said wall, said fusible body being slidablydisposed between said finger and said wall, and an alarm cord secured tosaid body.

HAROLD C. SORENSEN.

REFERENCES CITED The following references are of record in the tile ofthis patent:

UNITED STATES PATENTS

